Grating expansion joint for bridges



Patented' May 24, 1938 UNITED STATES PATENT OFFICE Ernest L. Tarot,Brooklyn, N. Y., assigner to Kerlow Steel Flooring Co., Jersey City, N.J., a corporation of New Jersey Application February 17, 1937, SerialNo. 126,102

Claims.

This invention relates to grating expansion joints for bridges and thelike and has for its object to eliminate disadvantages inherent in manyof the previously used types of such joints. Another object is toprovide such an expansion joint which is especially adapted for use withthe type of metal gratings which we manufacture.

One common form of expansion joint on the highway portion of bridges hasbeen a butt type joint which is practically vclosed in hot summerweather but wide open in cold weather. In many places the distance orsizeof gap which is open in such types of expansion joint in coldweather may be as much as about three inches, which is too large a 'gapfor trame to pass over smoothly, with the result that heavy trucks causesubstantial impacts which needlessly impair the joint. Another type ofexpansion joint in use has involved oppositely extending tapered fingerswhich overlap longitudinally various amounts according to thetemperature or season. An objection to this type of expansion joint isthat ice forms on `the vsides of the overlapping lingers due to theirbeing laterally spaced only a small amount, perhaps about a quarter ofan inch. This formation of ice is sufliciently serious to impede thefunctioning of the expansion joint and it has been necessary tohaveworkmen with blow torches go around and melt the ice thus formed. Underthis invention the tendency of ice to form at the expansion jointisjsubstantally minimized.

Referring to the drawing, Fig. 1 is a top plan view of one embodiment ofthis invention.

Fig. 2 is a section on the line 2-2 of Fig. l.

Fig. 3 is a section on the same line of Fig. l, but with the gratingsections Widely spaced, as in very cold weather.

Fig. 4 illustrates a modied type of expansion joint.

Fig. 5 shows a further type of expansion joint adapted for use withgrating sections.

Fig. 6 is a lift or bascule type bridge for which the expansion joint ofFig. 5 is particularly adapted when used with my open grating door.

A grating section I0 on a bridge or the like is movable with respect tothe end of an adjacent grating section II, so that these adjacent endportions are quite close together in very hot weather but contract andform a space, I2, between them which may vary up to possibly threeinches in the very coldest weather. Each grating section, I0 and II, maybe of any convenient length and may include several or any desirednumber of such lengths which are fastened together for expansion orcontractile movement as a unit. Preferably each such section is anchoredto one of its transverse supporting beams adjacent its central portionin order that the ex pansive movement of each section may be on bothsides of such anchorage. Ordinary beams I3 and Il, extend transverselyacross the bridge for supporting these grating sections we manunfacture. Each grating section is preferably comprised of straight bars,I5, and spacing bars, I6, which are riveted or welded to the straightbars. Any convenient type of spacing bar may be used such as thatillustrated or the substantially normal type bar. vA splicing section,I1, is provided to support the adjacent end portions of the gratings,Ill and II, and also for the purpose of providing a ller or bridge whenthe gap, I2, is large, in order that vehicular trailic may -travel overthe open gap with a minimum amount of vibration. This splicing sectionincludes a number of longitudinal members arranged contiguous alternatelongitudinal members of the grating sections, or, if desired, they maybe arranged contiguous each longitudinal member of the grating sectionsI0 and II. As illustrated in Fig. 1, this splicing section has itslongitudinal portions arranged contiguous alternate longitudinal gratingmembers and connected tothe longitudinal straight bars by headedsecuring means, I8, passing through elongated slots, I9, located belowthe spacing bars in order that limited relative movement may take placebetween the splicing section and each grating section.

The longitudinal portions of the splicing section Il are preferablysupported on the transverse beams, I3 and I4, as illustrated and soshaped as to t between these beams and contiguous their sides so thatthe splicing section longitudinal portions are substantially fixed whilethe adjacent ends of the grating sections, I0 and I I, are movable withrespect thereto with temperature change. 'I'he longitudinal portions ofthe splicing section may be connected by spacing portions below thelongitudinal straight bars of the grating sections, I0 and Il, assuggested in my Patent 2,014,912, dated September I7-, 1935. 0r, ifdesired, the various longitudinal bars of the splicing section I1 may bedisconnected except as they are connected through the grating sections.The top of the splicing sections preferably is contiguous the under sideof the spacing bar, I B, to assist in supporting the overhanging ends ofthe grating sections. In the embodiment illustrated, the headed securingmeans, I8, which may be either a bolt or a rivet, is xed with respect tothe portion of the straight bars, l5, through which it passes beneaththe spacing bar, I6, while the slots, i9, are shown as being provided inthe splicing section.

The central portion of the splicing section is raised as shown at 2|, toa height substantially ilush with the top of the grating sections, i0and Il, so that when the grating sections are widely spaced apart, thisraised portion, 2 I, serves as a bridging element to facilitate smoothtravel of vehicular traic over the joint in cold weather withoutobjectionable impact. As shown in Fig. 1, this raised or bridgingportion. 2i, lies contiguous alternate straight bars, I5. If it is desired for the splicing section longitudinal members to be contiguouseach of the longitudinal straight bars, l5,l thenvthe raised portion,2|, in alternate straight bars must be considerably shorter than thatshown in Figs. 1 to 3, or else the bent spacing bar, I6, will have to beterminated at alternate straight bars, I5, back from the ends ofalternate straight bars of each section rather than allowed to extend tothe ends of alternate straight bars as illustrated in Fig. 1.

In Fig. 4, the'long'itudinal portions, I'la, of the splicing section arearranged between rather than on the same side of the straight bars, lia,of each grating section. .This arrangement has the advantage of enablingthe longitudinal straight bars of. each grating section to overlap eachother longitudinally, if desired. In each embodiment the bent bars mustbe shaped to allow the necessary relative movement between the splicingsection straight bars and the grating sections. Here again thelongitudinal portion of the splicing sections may be laterally connectedor not, as desired, below the straight bars of the grating sections.

In Fig. 5 is shown another form of expansion joint adapted for use withgrating sections. This type of joint will be seen to compriseoverlapping straight bar extensions, 23, which are formed beyond thetermination of the bent bars, I6b, and the straight bars, l5b, are shownas being laterally spaced about midway between pairs of the straightbars of the other grating section. An expansion joint of this type ispreferably used without the splicing section described in connectionwith Figs. 1 to 4, inclusive. Since the spacing between straight barsoi'. a grating section is generally inV excess of two inches, thelateral spacing between the overlapping ngers, 23. is generally inexcess of an inch, with the result that any tendency for ice to form onthe sides of the overlapping bars, 23, is greatly minimized. Theexpansion joint shown in Fig. 5 is especially adapted for use with liftor bascule type bridges the adjacent end portions oi which may beslightly overlapped. ,Such a bridge is illustrated in outline in Fig. 6,where the bascules 2li are pivoted at 25, as is customary.

Among the advantages of this invention may be mentioned the eliminationof any exposed surfaces adjacent the expansion joint on whichsubstantial quantities of snow or ice may collect. The relatively narrowedge surfaces provided in gratings allow for very little snow or ice tocollect. The provision of a raised or bridging part to the splicingsection permits vehicular traffic to travel over a wide gap in coldweather with little or no impact comparable to what might occur if theraised or bridging portions were absent. While the splicing section hasbeen illustrated as being anchored and movable with respect to eachgrating section, nevertheless, it will be understood that if desiredthis splicing section may be fastened with respect to eithergratingsection and movable with respect to the other. The splicing section ofthis invention may serve the combined oillce of both a splicing sectionto support the ends of adjacent gratings and also as a bridging part oian expansion joint. There is little or no tendency for ice to formbetween longitudinal portions of the expansion joint,`

either in Fig. 5 or in Figs. 1 to 4. It the adjacent ends of the gratingsections are oi' the type illustrated in Fig. 5, these sections may havetheir straight bars in substantial alignment when the raised portion ofa splicing section may be placed contiguous each straight bar, or itdesired, a. splicing section between adjacent straight bars as in Fig. 4may be used with the grating ends of the type shown in Fig. 5. In eventan unusually hot day may expand the grating sections shown `in Fig. 5until the ends of the bars, 23, abut the spacing bars, lib, that shouldnot be objectionablev for it shouldbe a relatively simple matter foreither the ends, 23, or the bent bars, I6b, to be bent by expansion andcontract as may be necessary. From Fig. 5, it may be seen that if theilngers, 23, have their ends abutting the bent bar, llb, the .tendencyof any of the bars to be bent is balanced due to the symmetricalarrangement of the spacing bars, lib.

I claim:

1. A grating expansion joint between sections for a bridge and overwhich vehicular tralc is adapted to pass, comprising longitudinalmembers adapted to move toward and from each other as portions of. saidbridge expand and contract, a longitudinal member overlapping portionsof said first mentioned longitudinal members, having an extensionsubstantially ush with the top of said sections, adapted to -bridge anygap between them and to assist in directly supporting vehicular trafllcas it. pass over such gap, said second mentioned longitudinal memberbeing slidably secured to the rst mentioned longitudinal members so thatit need not move with them.

2. A grating expansion joint between sections for a bridge and overwhich vehicularv trame is adapted topassI comprising longitudinalmembers adapted to move toward and from each other as portions of saidbridge expand and contract, a longitudinal member overlapping portionsof said first mentioned longitudinal members, having an extensionsubstantially flush with the top of said sections, adapted to bridge anygap between them and to assist in directly supporting vehicular trailcasit passes over such gap, said second mentioned longitudinal member beingslidably secured to at least one of the iirst mentioned longitudinalmembers so that it need not move with them, and means for holding saidsecond mentioned longitudinal member against movement with at least oneof said rst mentioned longitudinal members.

3. In a bridge or the like paved with metal grating sections adapted tobe moved toward and from each other longitudinally with expansion andcontraction of said sections, each section including longitudinalsubstantially straight bars having 'spacing bars secured between themand of less depth than the straight bars, a splicing section havinglongitudinal members secured to at least some of. the longitudinalmembers of said sections by headed securing means fastened to thelongitudinal Amember of one section and passing through a longitudinalelongated slot in the contiguous longitudinal member, said splicedsection having an elevated portion centrally thereof rising to a heightsuch that its top is substantially flush with the tops of said gratingsections.

4. In a bridge or the like paved with metal grating sections adapted tobe moved toward and from each other longitudinally with expansion andcontraction of said sections, each section including longitudinalsubstantially straight bars having spacingV bars secured between themand of less depth than the straight bars, the straight bars of onesection being laterally displaced from the straight bars in the othergrating section, an expansion joint being formed between said sec tionsso that a longitudinally extending portion of one section substantiallyoverlaps another longitudinally extending portion of theother section toprevent the formation of an open gap longitudinally between the sectionsat the top or tread surface of said paving, said joint including asplice section secured to the longitudinal straight bars of each sectionbelow their spacing bars and having an extension substantially flushwith the top of said sections at their ends.

5. In a bridge or the like, an expansion joint formed between metalgrating sections which are adapted to be moved toward and from eachother longitudinally with expansion and contraction of said sections,each section including longitudinal substantially straight bars havingspacing bars secured between them and of less depth than the straightbars, spaced transverse beams on which said sections are supported, asplicing section overlapping the adjacent end portions of said sectionsin said joint, and being supported at its ends on adjacent portions ofsaid sections, a slidable connection between said splicing section andthe adjacent end portions of said grating sections, said splicingsection being anchored to at least one of said transverse beams.

6. In a bridge or the like, an expansion joint formed between metalgrating sections, which are adapted to be moved toward and from eachother longitudinally with expansion and contraction of said sections,each section including longitudinal substantially straight bars havingspacing bars secured between them, spaced transverse beams on whichsections are supported, a splicing sec-v tion overlapping the adjacentend portions of said sections and including longitudinal bars slidablysecured to longitudinal bars of each grating section, said splicingsection being located contiguous and on opposite sides of adjacentlongitudinal bars in said grating sections. the longitudinal bars of thesplicing section having an extension which is substantially flush withthe tops of said grating sections.

7. An expansion joint between metal grating sections comprising asplicing portion attached to at least one of said grating sections,having a part which is substantially flush with the tops of saidgratingsections and which is adapted to longitudinally overlap the endsof said grating sections.

8. The combination with a pair of metalgrating sections adapted to havea space between their adjacent ends, of longitudinal members overlappingsaid sections, forming anexpansion joint and provided with raisedportions substantially ilush with the tops of said grating sections attheir ends, and supports for said grating sections and longitudinalmembers.

9. A grating expansion joint for a bridge and over which vehiculartrailic is adapted to pass, comprising longitudinal members adapted tomove toward and from each other as portions of said bridge expand andcontract, a longitudinal member overlapping portionsl of said iirstmentioned longitudinal members, adapted to bridge any gap between themand to assist in directly supporting vehicular tramo as it passes oversuch gap, said second mentioned longitudinal member being slidablerelatively to at least one oi' the iirst mentioned longitudinal members,said second mentioned longitudinal member having its end portionsprovided with supporting means which is in addition to any connection toeither of the ilrst mentioned longitudinal members.

l0. A grating expansion joint for a bridge over which vehicular trafilcis adapted to pass, comprising grating sections which are adapted to bemoved relatively toward and from each other longitudinally withexpansion and contraction oi said sections, each section includinglongitudinal substantially straight bars having bent spacing barssecured between them and of less depth than the straight bars, splicingbars secured to at least some of the straight bars of said sectionsbelow the spacing bars and provided with raised portions substantiallyush with the tops of said sections and bridging any gap between the endsof no more than alternate ones of said straight bars when the spacingbars extend substantially

